Unitary fan evaporator assembly

ABSTRACT

In the preferred form, a refrigerator cabinet is provided with a sheet metal outer shell and a plastic inner liner with polyurethane foam insulation in between. The interior of the inner liner is divided into an upper freezing compartment and a lower above freezing compartment by a sheet metal wall having a lower portion in the rear and a higher portion in the front. Above this lower portion there is provided cast foam insulation beneath an evaporator compartment having inlets extending to it from the front of the upper freezing compartment and from the lower compartment through the portion of the sheet metal wall between the lower and higher portions. Resting upon the cast foam insulation is a large drain pan which extends beneath and supports a tubular horizontally extending evaporator having upright fins extending from the front to the rear. The drain pan also has brackets and a vibration-absorbing mounting for supporting the fan motor at the rear of the evaporator having a drive shaft extending rearwardly through the rear wall of the inner liner where it is provided with a side inlet centrifugal fan which draws the air through the inlets and the evaporator and discharges it into an upwardly extending duct extending to the upper compartment and a downwardly extending duct extending to the lower compartment, both of which are housed in the plastic foam insulation between the rear walls of the inner liner and outer shell.

United States Patent Primary ExaminerWilliam J. Wye Att0rneys-William S.Pettigrew, Frederick M. Ritchie and Edward P. Barthel ABSTRACT: In thepreferred form, a. refrigerator cabinet is provided with a sheet metalouter shell and a plastic inner liner with polyurethane foam insulationin between. The interior of the inner liner is divided into anupperfreezing compartment and a lower above freezing compartment by a sheetmetal wall having a lower portion in the rear and a higher portion inthe front. Above this lower portion there is provided cast foaminsulation beneath an evaporator compartment having inlets extending toit from the front of the upper freezing compartment and from the lowercompartment through the portion of the sheet metal wall between thelower and higher portions. Resting upon the cast foam insulation is alarge drain pan which extends beneath and supports a tubularhorizontally extending evaporator having upright fins extending from thefront to the rear. The drain pan also has brackets and avibration-absorb ing mounting for supporting the fan motor at the rearof the evaporator having a drive shaft extending rearwardly through therear wall of the inner liner where it is provided with a side inletcentrifugal fan which draws the air through the inlets and theevaporator and discharges it into an upwardly extending duct extendingto the upper compartment and a downwardly extending duct extending tothe lower compartment, both of which are housed in the plastic foaminsulation between the rear walls of the inner liner and outer shell.

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ATTORNEY UNITARY FAN EVAPORATOR ASSEMBLY This invention relates tomultiple-compartment frost-free.

refrigerators.

Frost-free refrigerators with effective foam insulation are verydesirable. However, the sales of such refrigerators have been restrictedby higher costs.

It is an object of this invention to provide a unitary refrigeratingassembly for frost-free refrigeration which can be economically mountedwithin the inner liner and which can be economically manufactured andtested as a separate unit.

It is also another object of the invention to provide a refrigeratingunit within the inner liner which will be compact which will make use ofthe least desirable space within the refrigerator.

It is another object of this invention to provide a refrigerator withupper and lower compartments and a unitary refrigerating unit and fan ina dividing wall between the compartments which cooperate withdistributing ducts in the rear wall of the cabinet.

Further objects and advantages of the present invention will be apparentfrom the following description; reference being had to the accompanyingdrawings, wherein preferred embodiments of the present invention areclearly shown.

In the drawings:

FIG. 1 is a front view partly in section of a frost-free refrigeratorembodying one form of my invention;

FIG. 2 is a fragmentary horizontal sectional view taken through thedividing wall along the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary vertical sectional view including the dividingwall taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a top view of the assembled cast insulation pieces partiallyshown in FIG. 3; and

FIG. 5 is an exploded perspective view of the cast insulation pieces andthe refrigerating unit shown in FIGS. 2 to 4.

Referring now to the drawings and more particularly to FIGS. 1 and 2,there is illustrated a refrigerator cabinet including an outer sheetmetal shell 120 having inturned front flanges 122 extending around thefront opening of the shell. Within the outer shell 120 is a one-pieceplastic inner liner 124 having a bottom wall provided with a front lowersection 126 and a rear higher section 128 over the motor compressor 130and the condenser 132. The inner liner and outer shell include spacedrear walls 134 and 136. Plastic foam insulation 138 containing aninsulating gas is provided between the inner liner 124 and the outershell 120 which reinforces both the inner liner and outer shell andincreases the rigidity of the structure so that separately the innerliner and outer shell need not be rigid.

According to my invention, within the inner liner 124 I provide animproved form of horizontally extending dividing means 140 forming anupper subcompartment 142 to be maintained at below freezing temperaturesbetween about 0 and F. and a lower above freezing compartment 144 to bemaintained at above freezing temperatures of about 36 F. This lowercompartment 144 may be provided with two or more horizontal shelves 145.

The top wall of the lower subcompartment 144 is provided by a sheetmetal wall 146 forming the bottom of the dividing means 140. The wall146 includes a higher portion 148 at the front and a lower portion 450at the rear with a slanted connecting section 152 in between the frontand rear portions provided with air inlets 151 to the evaporatorcompartment 153 above. This wall 146 preferably is supported at the rearby plastic supports (not shown) composed of glass fibers and hightemperature thermoset plastics such as polyester or phenolformaldehyderesin. The wall is supported at the front by a transverse metalcrossmember 156 extending between the inturned flanges 122 ofthe outershell 120.

Resting upon the lower portion 450 is a cast foam insulation piece 158supporting a unitary removable cooling assembly 451 in which the drainpan 12 serves as a supporting frame and extends beneath substantiallythe entire unit. It is curved upwardly at the edges and at the sides andat the rear it is provided with upwardly extending side and rear walls160,162. Within the rear comers are L-shaped supporting brackets 164 andat the center rear there is provided a pair of Z-shaped supportingbrackets 166 to which is connected a U-shaped fan motor bracket 167 anda transverse end motor bracket 179 extending across the open portion ofthe U-shape.

Connected to the L-shpaed brackets 164 by threaded fasteners are the endplates 33 of a refrigerant evaporator 24 having horizontal pieces oftubing extending in serpentine fashion through the cross fins 32extending from front to rear. This refrigerant evaporator 24 isgenerally rectangular on all sides with the end portion being generallynearly squareshaped. As shown, the fins 32 are arranged in a front and arear section with a cut out extending up from the bottom in between thetwo sections for receiving a transversely extending radiant heat type ofdefroster heater 506. The ends of this radiant heat defroster heater aresupported by spring brackets 37 riveted to and protruding outwardly fromthe end plates 33. This central location for the radiant heater assuressufficient downwardly directed radiant heat to melt any ice in the drainpan 12 beneath and assures substantially direct radiant emission to allparts of the evaporator within a relatively close range. To prevent thedefrost water from dripping onto the radiant heater 506 the tops of theopenings in the fins are provided with narrow annular oppositelyextending flanges 38 which form sort of a cover over the radiant heater.

The outlet of the evaporator 24 is connected to a receiver 27 extendingdiagonally upwardly in front of the evaporator above the front of thedrain pan 12. The upper end of this receiver 27 is connected by theLshaped tubing 28 to the stem of a T connection 6. The left half of thestraight through portion of the T connection 6 connects to the inlet 23of the evaporator 24 beneath the receiver 27. A capillary liquid supplytube 19 has its discharge end extending through the straight throughportion of the T connection and the necked in portion of the inlet tube23 for discharging liquid refrigerant thereto. This capillary tube 19extends through the straight portion of the T connection 6 and throughthe coiled portion 22 of the suction line 20 to the machinerycompartment below. The capillary tube 19 emerges from the suction line20 in the machinery compartment 168 beneath the cabinet. The suctionline 20 is provided with a T connection connecting with the inlet tube170 of the sealed motor compressor unit 130. This provides a simplesingle entry arrangement in which the concentric capillary supply tube19' and the suction conduit 20 can be readily passed through a doublegrommet 172 located in the rear wall for connection with the condensingsystem beneath the cabinet.

The sealed motor compressor unit 1311 draws refrigerant from the inlettube 170 and discharges the compressed refrigerant into a condenser 132from which liquid refrigerant flows through a loop of tubing 174provided inside the inturned flanges 122 around the door opening of thecabinet. The outlet end of this loop connects with a filter drier 176connecting to the capillary supply tube 19. This loop of tubing 174further disipates to the outer shell some of the heat of the liquidleaving the condenser 132 to provide additional cooling of the warmliquid. It also contacts brackets supporting the crossmember 156 andserves the purpose of preventing sweating or moisture condensation onthe cabinet shell adjacent the door openings.

The upper and lower subcompartments 142 and 144 are closed by an upperdoor 178 and a lower door 180. The cooling assembly is made separatefrom the motor compressor condenser assembly and these are separatelyinserted into the cabinet with the combined suction conduit 21) andcapillary tube 19 being passed through the grommet 172 and their endsconnected to the inlet tube 170 and filter drier 176. The coolingassembly 451 also includes a fan motor 13 having concentric hubs at theends of its axis which are held within vibration absorbing rubber rings14 which are mounted in apertures in the fan motor supporting members167 and 179. The fan motor has its drive shaft extending rearwardly andprovided with a side inlet type centrifugal-type fan 91. The rear walls162 are provided with a fan housing orifice 90 extending around the sideopening of the fan in the vicinity of the peripheral blades of the fan91. The fan 91 projects through an opening 182 in the plastic liner 124.

Located in the insulation of the rear wall is a plastic duct 74including a central scroll section surrounding the fan 91 and a wideupwardly extending duct portion 184 extending up to an upper outlet 186in the rear wall 134 of the plastic liner 124 through which the air fromthe fan is discharged into the upper subcompartment 142. The downwardlyextending duct portion 188 extends to a smaller outlet 190 for thedischarge of air into the lower compartment 144. These ducts and outletsare so proportioned to the size and heat leaks of the upper and lowersubcompartments 142 and 144 so that the upper subcompartment ismaintained at the desired temperatures of between and F. and the lowersubcompartment 144 is maintained at a temperature of about 36 F. The fan91 draws air from the upper subcompartment 142 through the inlets 191 atthe front of the plastic bottom wall 193 of the compartment 142 into theevaporator compartment 153. The evaporator 24 is insulated from thecompartment 142 by a slab 195 of insulation located between the wall 193and the evaporator- 24. Air is. also drawn from the lower subcompartment144 vthrough the openings 151 into the evaporator compartment 153 fromwhich the combined air is drawn through the evaporator 24 and dischargedby the fan 91 through the scroll section of the duct 74 and the duct 188and outlet 190 to the lower subcompartment 144. The cooling assemblyalso includes wiring 117 including a pair of conductors 61 and 64connecting with the fan motor 13 and conductors 192 and 194 connectingwith the terminals 196 and 198 upon the ends of the radiant defrostheater tube 506. The conductor 194 connects to a defrost limiterthermostat 115 mounted in a bracket 116 on the right rear wall portion162. The defrost limiter switch 115 connects to the conductor 221. Allthis wiring ex tends from the fooling assembly through the doublegrommet 172 in the rear wall to the remainder of the system in themachine compartment 168 below.

With this arrangement the entire unit supported by the drain pan 12 canbe built and assembled and wired as a separate unit and then testedprior to its assembly into the cabinet. This makes the cabinet assemblymuch more convenient and less expensive and makes it possible to correctany defects and improper assembly before its assembly into the cabinet.This reduces delays in the cabinet assembly line due to rejections ofparts in the refrigerating system and makes for a much more economicalmanufacture with improved qualities of workmanship.

The cast foam insulation piece 158 includes a supporting ledge 223extending around a central aperture 225 beneath the drain pan 12.Extending above the ledge 223 is a front wall 227 containing threenotches 229 forming air passages which are aligned with the threeopenings 151 in the sheet metal bottom wall 146. Also above the ledge223 are the integral sidewalls 231 which insulate the walls 160 and theintegral rear walls 233 which insulate the walls 162 and which aredivided to provide an opening for the fan 91. The ledge also includes anotch 235 for the drain trough 237 (FIG. 3) which extends from theoutlet in the bottom of the drain pan 12 rearwardly to the rear wall134. A plastic bag 239 of polyethylene or other suitable plasticcontaining mineral wool or glass fibers is located in the largerectangular opening 225 beneath the drain pan 12 and the trough 237 toprovide a form of insulation which will substantially obstructtransmission of moisture vapor to the bottom of the drain pan 12. Theinsulation piece 158 is also provided with a groove 241 for therefrigerant conduit and with groove 243 for the electrical conductors117 extending through the corner ofthe right rear wall 233.

A second cast insulation piece 245 is provided between the front portionof the bottom member 193 of the below freezing compartment 142 and theuppermost portion 148 of the sheet metal wall 146. The rear portionoverlaps the front wall 227 of the piece 158 to extend over the passages229 therein. This front piece contains wide passages 247 between thesupports 249 which conduct the air from the entrance 191 in the wall 193to the evaporator chamber 153. The piece 245 keeps the air from thecompartments 142 and 144 separated until they reach the evaporatorcompartment 153. The insulation pieces 158 and 245 may be cast ofpolystyrene beads or of polyurethane foam or any other suitable form ofplastic foam insulation. These insulation pieces are light and easilyhandled and effectively guide the flow of air between the compartments141 and 142 and the fan 91 so that restrictions to flow are minimizedand the flow is substantially evenly distributed over the evaporator451. The split rear walls 233 are wedge-shaped and thinner at the centerso that they diverge away from the rear of the evaporator 24 as theyapproach the fan 91 to provide a flat triangular plenum chamber for theuniform drawing of the air from the rear face of the evaporator 24 bythe fan 91.

While the embodiments of the invention as herein disclosed constitutepreferred forms, it is to be understood that other forms might beadopted.

1 claim:

1. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a dividing means within said inner linerdividing said compartment into subcompartments wherein the improvementcomprises a sheet member upon the bottom of said dividing means having ahigh portion and a low portion and an offset between said high and lowportions, said dividing means having an insulated compartment above saidlow portion, a subassembly located in said insulated compartment in saiddividing means above said low portion, said subassembly comprising adrain pan located in the lower portion of said insulated compartment andan evaporator supported on said drain pan adjacent said offset and a fanand fan motor supported on said drain pan on the opposite side of saidevaporator from said offset, said dividing means having suction passagemeans extending from the subcompartment beneath said high portionthrough said offset to said insulated compartment and suction passagemeans extending from the subcompartment above said dividing means tosaid insulated compartment, and discharge passage means extending fromsaid fan to said subcompartments.

2. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a laterally extending dividing meanswithin said inner liner dividing said compartment into upper and lowersubcompartments wherein the improvement comprises, a sheet member uponthe bottom of said dividing means having a high portion adjacent thefront of said cabinet and a low portion adjacent the rear of saidcabinet and an offset between said high and low portions, said dividingmeans having an insulated compartment at the rear of said offset abovesaid low portion, a subassembly located in said insulated compartment insaid dividing means above said low portion comprising a drain panlocated in the lower portion of said insulated compartment and anevaporator supported on said drain pan and a fan and fan motor supportedon said drain pan on the opposite side of said evaporator from saidoffset, said dividing means having suction passage means extending fromthe upper and lower subcompartments to said insulated compartmentbetween said offset and said evaporator, and discharge passage meansextending from said fan to said upper and lower subcompartments.

3. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a sheet member within said inner linerseparating the lower portion of said compartment from the space above,said sheet member having a high portion and a low portion and an offsetbetween said high and low portions, an insulation piece supported uponsaid low portion ofsaid sheet member and having an interior cavityproviding an insulated evaporator compartment above said low portion, arefrigerant evaporator located in said insulated evaporator compartmentand supported upon said insulation piece, said evaporator being providedwith an inlet side adjacent said offset and an outlet side on theopposite side of said offset, said insulation piece being provided withinsulating walls upon the sides of said evaporator and being providedwith inlet passage means between said offset and said inlet side of saidevaporator and being provided with an outlet passage means in the wallon the outlet side of said evaporator, fan means located adjacent saidoutlet passage means for drawing air through said inlet passage meansand said evaporator and said outlet passage means, and discharge passagemeans extending from said fan means to the lower portion of saidcompartment and to the space above.

4. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a sheet member within said inner linerseparating the lower portion of said compartment from the space above,said sheet member having a high portion and a low portion and an offsetbetween said high and low portions, a first insulation piece supportedupon said low portion of said sheet member and having an interior cavityproviding an insulated evaporator compartment above said low portion, arefrigerant evaporator located in said evaporator compartment andsupported upon said insulation piece, said evaporator being providedwith an inlet side adjacent said offset and an outlet side on theopposite side of said offset, said insulation piece being provided withinsulating walls upon the sides of said evaporator and being providedwith air inlet notches in said wall between said offset and said inletside of said evaporator and being provided with air outlet passage meansin the wall on the outlet side of said evaporator, a second insulationpiece mounted on the high portion of said sheet member and extendingover the wall of said first men tioned insulation piece between saidoffset and the inlet side of said evaporator and extending above saidair inlet notches, said second insulation piece being provided with airpassage means extending from the space above to said insulatedevaporator compartment, said sheet member having air openingscommunicating with said notches in said first-mentioned insulationpiece, fan means located adjacent said outlet passage means for drawingair through said air openings in said sheet member and said air inletnotches in said wall and said air passage means in said secondinsulation piece and said evaporator and said outlet passage means, anddischarge passage means extending from said fan means to the lowerportion of said compartment and to the space above.

5. A refrigerator including a cabinet having an outer shell and an innerlinear enclosing a compartment, a sheet member within said inner linerseparating the lower portion of said compartment from the space above,an insulation piece in the general shape of a rectangle with a centralopening extending through its bottom and a supporting ledge extendingalongside said opening, a drain pan in said opening supported upon saidledge, an evaporator in said opening supported upon said drain pan, saidinsulation piece having air inlet passage means on one side of saidevaporator and air outlet passage means on the opposite side of saidevaporator, air entrance means extending from said compartment to saidair inlet passage means and discharge air passage means extending fromsaid air outlet passage means to said compartment, fan means forcirculating air through said air entrance means and said air inletpassage means and said insulation piece and said evaporator and said airoutlet passage means, and a plastic bag containing a fibrous insulationmaterial located within the opening in said insulation piece beneathsaid drain pan.

6. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a dividing means within said inner linerdividing said compartment into sub compartments wherein the improvementcomprises a preas sembled refrigeration and defrost subassembly capableof being electrically tested prior to its assembly into the cabinet forlocation in said dividing means, said subassembly comprising a sheetmetal drain pan having upwardly extending sidewalls and rear walls, arefrigerant evaporator extending over a major fportion of the drain panand supported by the dram pan, a an motor and shaft supported upon saiddrain pan between said evaporator and said inner liner, said fan motorsupported within the confines of said drain pan by means of a fan motorbracket secured to said rear walls, said inner liner being provided withan aperture located in substantial coaxial relation with said fan motorand shaft, said shaft extending through said aperture and being providedwith a fan located at least partially between the inner liner and outershell, duct means between said inner liner and outer shell extendingfrom said fan to said subcompartments, said dividing means havingpassages extending from said subcompartments to the side of theevaporator opposite said fan motor, a defrost heater supported by saidevaporator for removing frost from said evaporator, a defrost limiterswitch mounted upon said drain pan, and wiring supported by said drainpan connecting to said fan motor and connecting said defrost heater andsaid limiter switch in series circuit.

1. A refrigerator including a cabinet having an outer shell and an innerliner enclosing a compartment, a dividing means within said inner linerDividing said compartment into subcompartments wherein the improvementcomprises a sheet member upon the bottom of said dividing means having ahigh portion and a low portion and an offset between said high and lowportions, said dividing means having an insulated compartment above saidlow portion, a subassembly located in said insulated compartment in saiddividing means above said low portion, said subassembly comprising adrain pan located in the lower portion of said insulated compartment andan evaporator supported on said drain pan adjacent said offset and a fanand fan motor supported on said drain pan on the opposite side of saidevaporator from said offset, said dividing means having suction passagemeans extending from the subcompartment beneath said high portionthrough said offset to said insulated compartment and suction passagemeans extending from the subcompartment above said dividing means tosaid insulated compartment, and discharge passage means extending fromsaid fan to said subcompartments.
 2. A refrigerator including a cabinethaving an outer shell and an inner liner enclosing a compartment, alaterally extending dividing means within said inner liner dividing saidcompartment into upper and lower subcompartments wherein the improvementcomprises, a sheet member upon the bottom of said dividing means havinga high portion adjacent the front of said cabinet and a low portionadjacent the rear of said cabinet and an offset between said high andlow portions, said dividing means having an insulated compartment at therear of said offset above said low portion, a subassembly located insaid insulated compartment in said dividing means above said low portioncomprising a drain pan located in the lower portion of said insulatedcompartment and an evaporator supported on said drain pan and a fan andfan motor supported on said drain pan on the opposite side of saidevaporator from said offset, said dividing means having suction passagemeans extending from the upper and lower subcompartments to saidinsulated compartment between said offset and said evaporator, anddischarge passage means extending from said fan to said upper and lowersubcompartments.
 3. A refrigerator including a cabinet having an outershell and an inner liner enclosing a compartment, a sheet member withinsaid inner liner separating the lower portion of said compartment fromthe space above, said sheet member having a high portion and a lowportion and an offset between said high and low portions, an insulationpiece supported upon said low portion of said sheet member and having aninterior cavity providing an insulated evaporator compartment above saidlow portion, a refrigerant evaporator located in said insulatedevaporator compartment and supported upon said insulation piece, saidevaporator being provided with an inlet side adjacent said offset and anoutlet side on the opposite side of said offset, said insulation piecebeing provided with insulating walls upon the sides of said evaporatorand being provided with inlet passage means between said offset and saidinlet side of said evaporator and being provided with an outlet passagemeans in the wall on the outlet side of said evaporator, fan meanslocated adjacent said outlet passage means for drawing air through saidinlet passage means and said evaporator and said outlet passage means,and discharge passage means extending from said fan means to the lowerportion of said compartment and to the space above.
 4. A refrigeratorincluding a cabinet having an outer shell and an inner liner enclosing acompartment, a sheet member within said inner liner separating the lowerportion of said compartment from the space above, said sheet memberhaving a high portion and a low portion and an offset between said highand low portions, a first insulation piece supported upon said lowportion of said sheet member and having an interior cavity providing aninsulated evaporator compartment above said low portion, a refrigerantevaporator locatEd in said evaporator compartment and supported uponsaid insulation piece, said evaporator being provided with an inlet sideadjacent said offset and an outlet side on the opposite side of saidoffset, said insulation piece being provided with insulating walls uponthe sides of said evaporator and being provided with air inlet notchesin said wall between said offset and said inlet side of said evaporatorand being provided with air outlet passage means in the wall on theoutlet side of said evaporator, a second insulation piece mounted on thehigh portion of said sheet member and extending over the wall of saidfirst mentioned insulation piece between said offset and the inlet sideof said evaporator and extending above said air inlet notches, saidsecond insulation piece being provided with air passage means extendingfrom the space above to said insulated evaporator compartment, saidsheet member having air openings communicating with said notches in saidfirst-mentioned insulation piece, fan means located adjacent said outletpassage means for drawing air through said air openings in said sheetmember and said air inlet notches in said wall and said air passagemeans in said second insulation piece and said evaporator and saidoutlet passage means, and discharge passage means extending from saidfan means to the lower portion of said compartment and to the spaceabove.
 5. A refrigerator including a cabinet having an outer shell andan inner linear enclosing a compartment, a sheet member within saidinner liner separating the lower portion of said compartment from thespace above, an insulation piece in the general shape of a rectanglewith a central opening extending through its bottom and a supportingledge extending alongside said opening, a drain pan in said openingsupported upon said ledge, an evaporator in said opening supported uponsaid drain pan, said insulation piece having air inlet passage means onone side of said evaporator and air outlet passage means on the oppositeside of said evaporator, air entrance means extending from saidcompartment to said air inlet passage means and discharge air passagemeans extending from said air outlet passage means to said compartment,fan means for circulating air through said air entrance means and saidair inlet passage means and said insulation piece and said evaporatorand said air outlet passage means, and a plastic bag containing afibrous insulation material located within the opening in saidinsulation piece beneath said drain pan.
 6. A refrigerator including acabinet having an outer shell and an inner liner enclosing acompartment, a dividing means within said inner liner dividing saidcompartment into subcompartments wherein the improvement comprises apreassembled refrigeration and defrost subassembly capable of beingelectrically tested prior to its assembly into the cabinet for locationin said dividing means, said subassembly comprising a sheet metal drainpan having upwardly extending sidewalls and rear walls, a refrigerantevaporator extending over a major portion of the drain pan and supportedby the drain pan, a fan motor and shaft supported upon said drain panbetween said evaporator and said inner liner, said fan motor supportedwithin the confines of said drain pan by means of a fan motor bracketsecured to said rear walls, said inner liner being provided with anaperture located in substantial coaxial relation with said fan motor andshaft, said shaft extending through said aperture and being providedwith a fan located at least partially between the inner liner and outershell, duct means between said inner liner and outer shell extendingfrom said fan to said subcompartments, said dividing means havingpassages extending from said subcompartments to the side of theevaporator opposite said fan motor, a defrost heater supported by saidevaporator for removing frost from said evaporator, a defrost limiterswitch mounted upon said drain pan, and wiring supported by said drainpan connecting to said fan motor and connecting said defrost heater andsaid limiter switch in series circuit.